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CLOSED  Feature request JPPF-624  -  Task dependency - depend on result of dependent task
Posted Feb 26, 2020 - updated Apr 25, 2020
icon_info.png This issue has been closed with status "Closed" and resolution "RESOLVED".
Issue details
  • Type of issue
    Feature request
  • Status
  • Assigned to
  • Type of bug
    Not triaged
  • Likelihood
    Not triaged
  • Effect
    Not triaged
  • Posted by
  • Owned by
    Not owned by anyone
  • Category
  • Resolution
  • Priority
  • Targetted for
    icon_milestones.png JPPF 6.3
Issue description
JPPF 6.2 introduced the concept of dependencies between Tasks and also between Jobs. It would be nice if this feature could be expanded with Tasks/Jobs having access to the result-value of the tasks/jobs it depends on.

Comment posted by
Feb 28, 08:48
Indeed, I agree that this is the logical and most useful thing to do.

For task graphs within jobs, I think we could refactor the communication protocol between driver and node such that the node receives the completed dependencies, if any, of each task it has to execute, and then provide an API to access those dependencies during execution.

For job graphs, it will be harder. Some possible approaches to explore, which are not mutually excludive:
  • use jobs persistence and provide a node-side API to access the stored job results
  • use a job task listener in the driver to aggregate the results of the tasks in a job, and then provide an API to access the aggregated results
Comment posted by
Mar 15, 11:32
Did a first implementation for graphs of tasks. Tasks can now see the resuts of their dependencies. Tested in simple and complex grid toplogies, including multi-server topologies